1. Field of the Invention
The present invention generally relates to a system and apparatus for generating electrical power. More specifically, this invention is directed to a hydroelectric turbine generator and computer based control system. The hydroelectric turbine generator can be installed and operated in low head, high volume “run of the river” hydroelectric sites throughout the world.
The hydroelectric turbine is specifically designed for small hydro applications and is not a “scaled down” larger turbine. The hydroelectric turbine takes advantage of the current state of the art technology, and applies it in the most appropriate manner for currently underutilized small hydro power sites. In Connecticut, Massachusetts and New York alone, there are 4,100 registered dams. Of these registered dams, approximately 350 are used for hydro power generation. There are approximately 3,750 undeveloped potential hydro power sites in this small region. In many cases, these are former mill sites with a prior history of hydro power production. There are an endless number of potential clean renewable power generating sites throughout the world, which can be developed using the present invention. Some of these sites are not former mill sites, are not registered dams and are currently considered to be not cost justifiable.
The present invention and technology will allow a vast, untapped, clean renewable power generating potential to be developed and utilized in a cost justified manner. Moreover, a hydroelectric turbine according to the present invention will open significant power production opportunities for other portions of the world including, “third world country” applications where the cost and complexities of current hydro equipment have made it difficult or impossible to consider.
2. Brief Description of the Related Art
Hydroelectric power generation is well known in the prior art. U.S. Pat. No. 4,674,279 to Ali, et al. (hereinafter, “the '279 Patent”) discloses a control system for a hydroelectric power plant of the run-of-river type wherein the load on the turbine generator unit(s) are matched to the flow of the river. The unit(s) operate at the maximum head available for existing flow conditions to produce the maximum energy available from the river flow for the installed capacity of the plant and within the allowable, safe operating capability range of the turbine-generator unit(s). The control system can be employed with a plurality of turbine-generator units in a hydroelectric power plant.
As disclosed in the '279 Patent, the turbine has a main housing and runner. Supply of water to the runner is controlled by wicket gates. The flow control means includes flow controls or modulating devices (wicket gates, runner blades or nozzles). The flow control means, or wicket gate position sensing, provides a signal indicative of the actual position of the flow control or wicket gates. The control system operates to cause either: (i) the opening of the flow control means or wicket gates to increase operation of turbine; or (ii) the closing of the flow control means or wicket gates to decrease operation of turbine. The control system automatically operates in response to variations in flow or in response to river conditions.
Other prior art discloses additional types of “Kaplan” style hydraulic turbines and control systems related to controlling the pitch of the runners and/or wicket gates. For example, U.S. Pat. No: 5,441,384 to Gokhman specifically describes a plurality of angles and a plurality of arrangements for wicket gates and blade runners. U.S. Pat. No: 4,610,599 to Long describes a control system for a hydraulic “Kaplan” turbine. More specifically this patent provides a method of control for adjustable wicket gates and adjustable blade runners in a hydraulic turbine.
U.S. Pat. No. 5,322,412 to Erlach (hereinafter, “the '412 Patent”) and U.S. Pat. No. 5,754,446 to Fisher, Jr. (hereinafter, “the '446 Patent”) describe a method for optimizing the controls of hydraulic “Kaplan” turbines. The '412 Patent describes the use of adjustable wicket gates and runners to optimize performance. The control system senses fluctuations in bearing pressure and/or generator AC output to change wicket gate and runner angles. Similarly, the '446 Patent describes the use of various sensors to control the adjustment of wicket gate and runner angles thereby optimizing the performance of the turbine.
None of these prior art disclosures provide a specifically designed hydroelectric turbine for use in small, micro or mini-hydro applications. Also, in the prior art, the relationship between the wicket gates and runner blades is dependent; the runner blade position is directly controlled by the wicket gate position rather than truly optimizing runner blade angle for maximum power output. Moreover, such prior art devices do not provide for a preconditioned flow by the wicket gate for optimal performance of the runner blade.
It is therefore an object of the present invention-to overcome these limitations in the prior art and to provide a hydroelectric turbine specifically designed for small hydro applications. It is also an object of the present invention to provide a means for independently controlling wicket gates and runner blades to achieve optimal power generation. Similarly, it is an object of the present invention to provide a means for preconditioning the flow to the runner blades by the wicket gates to achieve optimal power generation.